A new chapter – ammonia two-stroke engines
Contact our experts

Scroll down

Powering the maritime energy transition

Minimizing the impact of shipping on the climate and the environment is a crucial contribution to reaching the global climate targets. One of the ultimate goals is carbon neutral or carbon free transportation.

Currently, worldwide maritime transport emits around 3% of the global greenhouse gas (GHG) emissions. The International Maritime Organization (IMO) has set a target of net-zero CO₂ emissions from shipping by or around 2050. An ambitious goal that requires technological changes in the industry.

MAN Energy Solutions is leading the way in sustainable two-stroke engine innovation. We have a large portfolio and proven track record of dual-fuel engines that run on methanol, methane (LNG), LPG, or ethane. Following the successful start of single-cylinder tests of our MAN B&W two-stroke ammonia engine in 2023, we began full-scale engine tests in 2024. Ultimately, we are aiming to enable the delivery of the first ammonia engine, the MAN B&W ME-LGIA to a shipyard in 2025. As newbuild or retrofit, it will be a valuable addition to the existing MAN B&W two-stroke dual-fuel engine portfolio and will meet future market demands for green ship propulsion.

Ammonia – a new chapter in two-stroke engine history.

2025

1st engine delivery targeted to yard

95

%

ammonia fuel mix, based on L1 rating at 100% load

Proven two-stroke engine design

The ammonia two-stroke engine is based on the proven and trusted MAN B&W ME-LGI engine concept. It will be available as a newbuild engine or as a retrofit option for existing electronically controlled ME-C engines. The engine is currently under development at our Research Centre Copenhagen.

The development also includes safety measures such as ammonia containment systems, sensors, system ventilation and double-walled piping. In July 2023, we achieved the first combustion with ammonia on the two-stroke research engine, with highly promising data on the stability of the combustion process. During November 2024, the full-scale engine testing commenced, and will focus on, among other parameters, combustion and emissions, engine-tuning, atomizer testing and control-system verification. This is provisionally set to continue until mid-2025.

Watch the work.

By loading the video you agree to YouTube's privacy policy.

Load video

Always unblock YouTube

Ammonia engine: key benefits

Energy density and efficiency

Ammonia_Efficiency Ammonia can be used as an energy carrier of sustainable hydrogen and is carbon free. The two-stroke ammonia engine technology development aims for a small percentage of just 5% pilot oil at 100% load based on L1 rating*. The remaining 95% of the energy will be provided by ammonia while supplying you with high power, energy density, efficiency and extremely low emissions.

*Performance values indicated refer to energy fraction for L1 rated engines operating at 100% load point in Tier II mode. Actual values may vary depending on engine rating and load conditions.

Carbon- and sulphur-free

Ammonia is carbon- and sulphur-free and gives a clean combustion. Green ammonia as a fuel for shipping has the potential to become the sustainable future fuel choice, especially due to the expected lower production cost compared to other e-fuels such as e-methanol and synthetic natural gas.

Retrofits

The future installation of an ammonia combusting engine can be adapted to the customer. For example, as a dual-fuel, modular retrofit solution for existing electronically controlled engines. Talk to our experts about the best solution for your company.

Injection system for ammonia

The MAN B&W ammonia engine design philosophy

Ammonia mode

A small pilot flame is needed to start ammonia combustion. Initial tests were conducted with 10-15% pilot as a first step. The R&D target is around 5% pilot oil at 100% load for L1-rated engines.*

We target for the same heat rate as “fuel oil mode”. The ammonia engine concept will be based on the Liquid Gas Injection engine concept, which is well known from the existing methanol and LPG-fueled MAN B&W two-stroke dual-fuel engines.

*Performance values indicated refer to energy fraction for L1 rated engines operating at 100% load point in Tier II mode. Actual values may vary depending on engine rating and load conditions.

Fuel oil mode

We target identical performance as a conventionally fueled diesel engine.

Ammonia auxiliary systems

The auxiliary systems provide additional support to the MAN B&W ammonia engine and together ensure safe and efficient combustion. The ammonia catch system and the addition of absorbers make sure that no ammonia will be vented to the atmosphere above 5 ppm at our Research Centre Copenhagen.

Selective catalytic reduction technology

To reduce emissions of nitrogen oxides and to fulfil IMO Tier III emission regulations, engines from MAN Energy Solutions have been equipped with selective catalytic reduction (SCR) technology for many years.

The SCR system using ammonia was introduced in the 1990s in four bulk carriers.

It is an after-treatment process, where NO_X formed during combustion is removed from the exhaust gas in a catalytic reduction. Additionally, the SCR unit will be utilized to remove any ammonia slip from the exhaust.

Pending the outcome of the first engine test results, an increase in SCR volume and ammonia consumption may be necessary to achieve compliance in Tier III mode.

Alternative fuels for your two-stroke powered vessel: Ammonia, methanol and methane in focus
Watch the recording of our latest MAN ExpertTalk on alternative fuels for large merchant marine vessels. Get insights into the most promising marine fuels of the expected future fuel mix for two-stroke vessels, namely ammonia, methanol and methane.

You can also look forward to hearing about the latest product developments and applications as well as reasons why these fuels have the potential to offer a straightforward path for the future maritime energy transition.
Go to recording
Learn more about the two-stroke ammonia engine

MAN B&W ammonia engine development: Groundbreaking first engine test.

Learn about the progress of the development process and the successful combustion that was performed on a MAN B&W two-stroke 4T50ME-X type. Further, get insights about the design of the safety systems for fuel handling and the positive results that revealed particularly promising data regarding combustion stability.
Go to recording

Contact us

Talk to our experts for ammonia engines

You want to know more about our two-stroke ammonia engine and how it can suit your goals? Our global network of dedicated engineers will help you find the perfect solution for your business. Start your change process now and reach out to us today.

Contact our experts

Download the paper and learn more about the ammonia engine

MAN B&W two-stroke engine operating on ammonia
pdf, 733 KB

Download

Related news